This invention relates to an apparatus for manufacturing electric lamps such as a glow switch starter and a baseless lamp.
Generally, a method of manufacturing electric lamps, for example, a glow switch starter, includes a mount-making step of making a mount having a pair of leads, a stem tube and a bimetal piece welded to one of the leads; a bulb-making step of making a bulb; a sealing step of inserting the mount into the bulb and sealing one opening of the bulb; an evacuating step of evacuting the bulb, introducing an inert gas thereinto and sealing the bulb; and a lead-processing step of insulating the leads from each other and bending one of the leads.
Hitherto, an apparatus is proposed which is designed for the automatic and continuous manufacture of the glow switch starter through the above-mentioned steps. The conventional manufacturing apparatus comprises a mount-making unit provided with a plurality of equidistantly arranged mount heads and performing the mount-making step; a bulb-making unit; a sealing unit provided with a plurality of equidistantly arranged sealing heads and performing the sealing step; an evacuating unit provided with a plurality of equidistantly arranged evacuating heads and performing the evacuating step; and a lead-processing unit for performing the lead-processing step.
A chain conveyor is arranged between the mount-making unit and sealing unit, and another chain conveyor is arranged between the evacuating unit and lead-processing unit.
In the above apparatus, a mount made by the mount-making unit is shifted from the mount-making unit to the chain conveyor by a shifting mechanism. The chain conveyor transports the mount to the sealing unit. Then, the mount is shifted from the conveyor to the sealing unit by another shifting mechanism and is inserted into a bulb supplied from the bulb-making unit. The product constructed by sealing the bulb is carried to the evacuating unit. The product whose evacuation is completed is transported to another chain conveyor by means of a shifting mechanism. The bulb is delivered within proximity of the lead-processing unit by the chain conveyor and then shifted to the lead-processing unit by still another shifting mechanism. Thus, manufacture of the glow switch starter is concluded through the above-mentioned steps.
In the apparatus described above, the units are arranged in the order of the processing steps, thus ensuring the automatic, continuous manufacture of glow switch starters. As stated above, the chain conveyors are provided, one stretched between the mount-making unit and sealing unit, and the other stretched between the evacuation unit and lead-processing unit. The apparatus has two drawbacks. First, the shifting mechanisms are indispensable. Without them, the unfinished products cannot be transported from the fabricating units to the chain conveyors, or vice versa. Provided with these shifting mechanisms, the apparatus is so complex that a good deal of time should be spent on the maintenance and repair. Secondly, it takes some time to transport the unfinished procuts from the fabricating units to the chain conveyors, or vice versa. Hence, it is difficult with this apparatus to enhance the manufacture efficiency.
Furthermore, it is difficult to transport each ufinished product from every fabricating unit to every chain conveyor, or vice versa, at accurate time. Unless the product is transported at correct time, it will fall or crimped between the members of the conveyor or of the fabricating unit and will eventually damaged. In consequence, the yield of the product is low.